Method of manufacturing a game ball



Sept 3, 1940 w. J. vorr' er AL 2,213,479 A METHOD OF MANUFACTURING A GAME BALL Fil'ed Oct. 25, 1938 Patented sept. 3.11940 METHOD oF MANUFACTURING A GAME BALL william J. veit, Los Angeles, and Leith c. weimar,

South Gate, Calif.; said Weimer assignor to laid Application October 25, 1938, Serial No. 236,856

s-ciaims.

- This invention relates to game balls and especially to baseballs of the soft ball type in which a casing or cover encloses a center or core of compacted fibrous material.

A ball produced in accordance with this invention and the method of manufacture by which itI 4is produced are similar to the game 'ball and method of producing it constituting the subject matter of Patent No. 2,127,487, issued on August 16, 1938, to William J. Voit. The ball and manufacturing method of this invention represent an improvement upon the ball and manufacturing method described in that patent.

Balls of thisgeneral type comprise lcenters or' cores. of some fibrous material such as kapok, wool, cotton waste and the like, formed into generally spherical shape, and a cover for the center of rubber, leather, or other suitable wear resisting material. In the ball described in Patent No.,2,127,487 the kapok core is' wound with strands of yarn, cord, or other fibrous material,

- and a rubber cover is molded about this core.

That invention relates to the establishment of internal pressure within the core while the rubber cover is being vulcanized thereon within a mold, and to the subsequent relief of that pressure. This internal-pressure forces the material of the rubber cover into intimate contact with the inner.

surface of the mold to give the ball a true spherical shape, ,to cast accurately upon its outer.

surface designs which may be formed on the inner surface of the mold,- .and to insure an even distribution of the material of the cover in a' uniformly dense, solid layer devoid of soft spots.

The present invention has as one of its features the provision of an inner layer or wall of rubber, additional to the outer rubber cover of the abovementioned patent, for the two-fold purpose of rendering the internally established pressure more effective and providing a stronger, more durable outer casing for the ball.

Another purpose of the invention is the proviy sion of specific means of a novel character for the establishment .of internal pressure at the time of vulcanizing the ball, and of specific means of a novel character for the application of the cover 'material-to the core prior to vulcanization.

Another feature of our invention relates to the character of the core and has as its purpose means for preventing the core material from becoming unduly dry with the result that it i's pulverized by the heat of vulcanization or by treatment incident to its use in play.

Other objects will be apparent from the following description of our invention and from the game ball as an article of manufacture, such -g5 claims being the subject matterof a separate divisional application. Serial No. 347,894, for' a. Game ball, filed July 271940, by the same'inventors. n

Inthe drawing, g

Fig. 1 is a sectional view of the sphere of kapok which constitutes the central portion of the ball.

Fig. 2 is a sectional. view of the kapok sphere after it has been wrapped with a few-strands of 15 yarn. i

Fig. 3 shows in section the yarn-wound kapok sphere after it has been covered with an inner layer o'f rubber.

. Fig. 4 vshows in section the ball center after `the 20 next step has been performed of winding additional strands of yarn upon it. j

Fig. 5 shows in section the ball with the rubber' material of the outer cover in position ready for vulcanization.-

Fig. 6 is a sectional elevation of a ball within the mold completely ready for the step of vulcanization.

Fig. '7 shows in vertical elevation the completed ball.

Fig. is a fragmentary sectional view onan enlargedV scale showing rthe details of construction of the ball. A

Fig. 9 is a sectional elevation of a mold and ball center within the mold, ready for application 35 of the covering material according to an alternative method.

The first step in manufacturing the ball is the old and the mbled and methods familiar to those skilled in the art, of ce a compacted, roughly spherical mass ii of kapok. wool, cotton waste, or=iike material. One method of forming the ball ofkapok consists of pressing a. measured quantity of the kapok between two hemispherical metallic cups (not 45 shown). While thus compressed, a few threads are passed back `and forth between vthe mass o f kapok by means of a needle which is inserted through slits formed in the cups, and the ends 5'0 of the threads are tied, holding the kapok mass roughly to shape. The cups are then removed,- and a fewstrands l2 of yarn are wound around the kapok Il, by any convenient means. in sufcient number to prevent stray bers from proiecting from the surface of the center. The ball center then appears as shown in Fig. 2.

'I'he center is next placed in an air-tight chamber (no shown) into* which steam at a pressure of about 50 pounds is admitted. 'Ihe steam penetrates all parts of the kapok mass and meistens all of its fibers. It has been found that about a quarter of an ounce of water is absorbed in this way by the kapok of a 4 inch ball, and other amounts proportionately by balls of other diameters. Y

The saturated kapok mass II is then removed from the steam chamber.and after cooling is dipped in or otherwise coated with rubber' cement or latex, indicated in the drawing at Il, and is covered with a thin wall I5 of vulcanizable rubber. This Wall I5 is preferablygas-tight after it has-been applied and can be put on in any desired manner. spherical sheets of rubberin such manner that they are integrally joined at their meeting edges I8 to form a hollow sphere about the kapok.

'I'he ball at this stage in its manufacture is wound with. strands of yarn forming a layer I1 which is preferably of substantially greater thickness than'that of the strands I2. These strands are preferably coated with latex or the like before or during the winding operation. Under some conditions it may be preferred to use fabric woven from fibrous material implace of wound strands of yarn or thread. may be done by applying fitted sections of the fabric to the rubber wall I5.. which may be secured in position by rubber cement or any other. well known means. -The"\ center or core is then preferably dipped in or otherwise coated with latex or similar material, as indicated at I'Ia, and cov- A tegrally joined at f diameter of the finished b complished by the use ered with an outer casing ber which, like the Il of vulcanizable rubwall I5, is preferably made by applying twohemispherical sheetsof rubber to the ball center in such manner that they are intheir meeting edges Il. 'I'he ball is now completely assembled and ready for the molding' operation.- It has a diameter somewhat greater than the diameter which it is intended the finished ball shall have.

'I'he assembled ball is placed in a two-part mold 20, the cavity of which is a sphere of the e 'Since it is somewhat larger than the' cavity of the mold, the ball isslightly compressed when the mold parts are brought together. Y

An internal pneumacA pressure next established within the ball center. This may be aci of a hypodermic needle 2I to inject air or othe` uid through the outer rubberV cover I8, the strands II, and the inner rubber layer or wall I 5 into the ball center in th manner described in Patent No. 2 ,487, or it may be accomplished by means of a -producing chemical either in liquid form or in the form of a pill (not shown) placed somewhere in or upon the kapok center II prior to the application of the rubber wall I5 thereon. 'Such chemicals generate gas when heated, which in this case is effected by the heat used to vulcanize the ball in the mold. Thisinternal pneumatic pressure may also be created by wetting the kapok II with liquid ammonia before it is covered with the inner duced gas, ammonia gas. or steam establishes.

We prefer to apply two hemiwithin the ball center and within the gas-tight wall Il an internal pneumatic pressure which forces outwardly the wall Il. the layer of strands l of yarn II, and the outer cover Il against the inner face of the mold 20. While this pressure exists, a vulcanizing heat is applied to the mold. 'Ihe vulcanizable rubber of the outer cover I8 -in the softened condition induced by the vulcanizing heat .is pressed into intimate contact with the mold face and has formed on its outer surfaces smooth spherical contour broken only by the relief and indented markings 22 corresponding to the design impressed upon the mold walls. This design may be in simulation of the seams and stitches of a leather covered ball asshown at 22 in Fig. 7, or of any other desired character.

The heated soft rubber material of both the,

layers I5 and I8 is forced intol and between the strands of yarn of the layer I'I bythe pneumatic pressure within the ball. thoroughly impregnating the strands. the material of one layer meeting, coalescing. and becoming integrated with vthat of the other layer. After vulcanization, the

cover of the ball becomes a single integral structure of rubber 28 (Fig. 8) extending from the inner face of the inner laye'r I5 to the outer face of'- the outer wear resisting cover Il, in which are embedded strands of yarn I1. Such a cover is wear resisting, pliable, and, by virtue of the em-y bedded strands of yarn or cord, is resistant to circumferential stretching caused by blows delivered to it when infplay. Because of the integrated character ofthe cover, no relative displacement of its parts is possible, and the development of soft spots is delayed longer than is the casewith A baseball's of this type as now made.

When vulcanization is completed. the pressure within the ball is relieved.`either podermic needle or, if no needle is used, by puncturing the cover 28 as at 2l .(Fig. 8), thereby allowing the.compressed air, gas, or steam to issue from the center of the ball. The moisture within the ball center which remained therein at the time the kapok was subjected to contact with steam is partially retained when .the internal pneumatic pressure is relieved, serving to prevent the .kapok from becoming unduly dry when the 'heat' ofvulcanization is applied. In any event,

this applied moisture moisture, naturally present in serves to prevent loss of the kapoh, under the action of the vulcanlzing heat and subsequent venting of the ball center.

If they kapok is allowed ASI5 through the hybers are broken, and in some cases become finely pmverized both during vuicamzauon and after; ward-when the ball is being used in play, with the result that the ball loses the resiliency which is necessary for satisfactory performance. v After the pressure within the ball is relieved, the ballis removed from the mold and when cool is ready for use. It is to be observed that however the internal pneumatic pressure is created, it is essential that itbe relieved before the mold is parted. Otherwise rupture of the bali cover would occur. If the internal pressure only that caused by heat expansion of the alr,

or vaporization of moisture, normally present within the kapok, the pressure can be relieves-.i1 by the simple expedient of cooling the ball before removal of the mold from around it. If, however, additional pressure is desired in orderto form a more perfect cover, as described above, and such pressure is established by means of injected air or gas. or by means of gas generatedl `either by a Vchemical pill or by vaporization of dermic needle or by puncturing the outer cover' I8. f v

Fig. 9 shows an alternative means for applying the vulcanizable rubber material for the cover i8. Small metallic or stii rubber pins 26 are secured to the ball center, and these pins are used as a means of mounting the center within the mold parts 23 and 24. Thexpins are placed radially in the equatorial planeof the center coinciding with lthe plane of the meeting faces of the mold and are of sumcient length to project into small receiving grooves. (not shown) formed in these meeting faces. The pins serve to suspend the center between the two halves of the mold with the outer surface of the center concentrically spaced from the interior surface of the mold. y i

Vulcanizable liquid rubber is then forced under pressure through a conduit 29 into a chamber 2l so formed. The rubber material is forced into all portions of this -chamber and is brought into intimate contact with the face of the mold. The pressure of the liquid rubber also serves to put all the component parts of the ball under pressure, which may be augmented by the admission of air through a hypodermic needle or by any of the other means above outlinedl The ball is then vulcanized, the internal pressure relieved if advisable, and the ball removed from the mold as before.

En the drawings the thicknesses of the layers of rubber l5 and i8, the layers of rubber cement ld and lla., and the layers of yarn i2 and Il are magnied for clarity of disclosure. The thickness of the entire cover portion i8 of the ball from the outer surface of the kapok vmass il to the outer surface of the completed ball is, relative to the diameter of the mass of kapok, substantially less `than that shown in the drawing.

It .will be understood that vmany unessential variations in the structure of the ball and the method of manufacture can be made without departing from the spirit of this invention. The

-lrapchii may have a small central `core-of hard rubber or other material, or the kapel: maybe formed around a small hollow sphere of rubber or other material if it is desired to.V lighten the weight of the ball or secure some other desired result.

` The outenrubbercover may be pre-molded in sections, as in hemispherical cups, and during the molding operation may be either partiallyA or wholly vulcanized and have embossed thereon markings representing seams and stitching` or .other designs .molded on the' outer surface., These molded sections may then be applied to the ball center and vulcanized in place upon the layer oi yarn il ina mold'br by the simple application of heat, or the sections may be coated on" their inner face with self-curing liquid cement and applied to thegball center.v If molded upon the center,pressure may be appliedr inter-A nally as described above. I

If it is desired -to produce aleather covered ball, the process is modiied.V The ,outer rubber cover is applied as before, but is preferablyof less thickness. The leather Acover may-then be applied outside theffouter rubber cover, and any'v `.of the known methods of securing it to the ball may be used. The ball may be vulcanized prior moving said ball from said mold. f

to the application of the leather cover, or the leather cover may/be coated on the inn`er surface with latex Orliquidjrubber and 'applid to the unvulcanized7 outer rubber cover andthe completelyv assembled ball placed in the mold and vulcanized, either with or without the application of internal pneumatic pressure.

The word vulcanizable" has been used in the above description to describe rubber material, either solid or liquid, ywhich is capable of vulcanizatlon, and is applicable to rubber material which has been partially vulcanized as well as to that which has been subjected to nolvulcaniz-v ingaction.

' One main feature of this invention is the provision ina ball having a solid or substantially solid fibrous center of adouble-walled rubber `cover, between which is interposed elongated fibrous material, the entire cover being preferably integrally united. A cover of this character enables a more efficient use of internally applied pneumatic pressure to make a perfectlyv ing: taking a compacted. roughly shaped mass of material having the physical qualities of kapok; impregnating said mass witna supernormal content of water; applying a gas-tight, vulcanizable rubber envelope to said mass; covering said enveloped mass with elongated nbrous material to form. a ball center; enveloping said center with cover material comprising vulcanizable rubber material to form a ball; placing said ball in a mold; vulcanizing said ball; establishing pneumatic pressure Within said gas-tight 'rubber envelope prior to the completion of said vulcanization; relieving said pressure throughs. vent from said mass to thebail exterior; and re- 2. A method of making a game ball comprising: taking a compacted, roughly shaped mass of material having the physical qualities ofkalcanizable rubber envelope to said mass; covering said enveloped mass with elongated fibrous material to form a ball center; enveloping said;

. ing saidball frm said mold. y

3. A method of making a game ball comprispoki impregnating said mass with a supernormal content of water; applying a gas-tight vuling: taking a compacted, roughly shapedimass of material having the physical qualitiesof kapok; applying a gas-tight. vulcanizable rubber `envelope to said'mass; cvering said.enveloped mass with elongated ibroi'rs materialsbO- form a ball'center; enveloping said center' with cover material comprising vulcanizableV rubber material to"form a ball; placingsaid ball in a mold; vulcanizing .said ball; establishing pneumatic pressure withinsaid gas-tight rubber envelope prior to the completion of said vulcanization,

y whereby non-pneumatic, centrifugally acting, compressive stresses are mechanically applied to 75 impregnating said mass with a super-normal content of water; applying a gas-tight, vulcanizable rubber cover to said mass; vulcanizing saidv rubber cover with`heat; and venting water va- -por from said mass to the ball exterior.

5. A method of making a game ball comprising: forming a compacted fibrous core; applying a 'rst envelope of gas-tight, vulcanizable rubber to said core; covering said enveloped core with Vtension-resisting fibrous material to form a ball center; applying to said center a s econd` -envelope comprising vulcanizable rubber to form a ball; placing said ball in a mold; vulcanizing said ball by the application of heat; establishing pneumatic internal pressure within saidjrst gas-tight rubber envelope priorto the comple-- tion of said vulcanization, the degreeand vdura-- Ation oi' said heat and pressure being sumcient to cause Ythe rubber material o1' said rst envelope to.

' centrifugally permeate said brous material and of said second envelope to centripetally permeate saidiibrous material to such an extent thatthe two venvelopes are -united into one rubber env velope having imbedded therein said tension-re- 'sisting-iibrous material; relieving said pressure;

and removing said ball from said mold.

. 6; A method of making a game ball compris- Y ing: forming a compacted iibrous core; applying a iirst -envelope of 'gas-tight, vulcanizable rubber to said core; covering said enveloped core with tension-resistingvflbrous material to form a ball center; mounting said ball center with its outer surface inl uniformly spaced relationship with the inner walls of a mold; injecting.,under pressure vulcanizablev rubber into the spheroidal space between 'said center and said m'old; vulcanizing said ball bythe application of heat;

establishing pneumatic internal pressure within said'iii-st gas-tight rubber envelope prior to the completion of said vulcanization, the degree and duration of said heat and pressure being sufcintto cause .the rubber material in saidspace andthe rubber material of said rst envelope to` permeate said' brous material centr'ipetally'- and centrifugally respectively and mutually coalesce; relieving said pressure; and removing said ball from said mold.

A WILLIAM J. vorr. LEITH CJWETMER. 

